What are the differences between syphilis and rash?

Syphilitic rash is a rash unique to secondary syphilis patients. The characteristics of syphilis rash include a large number of Treponema pallidum in the skin lesions, which are highly infectious and can generally last for several weeks without treatment. The rash normally lacks specificity and can be manifested as erythema, papules, spots, papules, plaques, nodules, pustules or ulcers. It is often dominated by one type of skin lesions. Most of the rashes are generalized without itching, pain and other discomfort.